Ink feed device for fountain pens



Feb. 28, 1956 R. TANBERG INK FEED DEVICE FOR FOUNTAIN PENS Filed May 15, 1955 INVENTOR.

RAG/VAR TA/VBERG' B 4w! M United States Patent INK FEED DEVICE FOR FOUNTAIN PENS Ragnar Tanberg, Drammen, Norway Application May 13, 1953, Serial No. 354,677

1 Claim. (Cl. 120-45.4)

This invention relates to an ink feed for fountain pens of the type having interchangeable ink containers constructed for puncturing of the exchangeable container, and relates more particularly to an improvement in the construction of a combined puncturing needle and ink feed device in replaceable cartridge fountain pens.

By the known fountain pen constructions of this type, the ink container is punctured when the container is pushed into the shaft of the fountain pen against the sharp point of a hollow puncturing needle, which hollow needle serves the function of an ink feed to the pin point. This arrangement in prior art constructions results in a very short time in the development of a low pressure area in the ink container, which low pressure area prevents the ink going into the hollow needle and to the pen point. I

The object of this invention is to combine a hollow puncturing needle with an ink feed in such a manner that the ink is conducted from the ink container to the pen point, and air is fed in a counter direction into the ink container to relieve the vacuum and balance the pressure differential.

Another object of this invention is to provide a puncturing needle with the ink feed and air feed construction within the needle.

It is to be understood that the foregoing objects are directed to the basic physical properties of this invention, and that other objects and a fully understanding of the invention may be had by referringto the following description and claims taken in conjunction with the accompanying drawings in which:

Figure 1 is a side vertical sectional view of a fountain pen made according to the teaching of this invention, illustrating the replaceable ink container body with the improved needle and ink feed construction of this invention extending through a puncturable membrane into the interior of the container body.

Figure 2 is a fragmentary front sectional view through the puncturing needle and associated ink distribution system;

Figure 3 is a sectional view taken along line 3-3 of Figure 2; and

Figure 4 is a sectional view of an alternate needle and ink feed construction.

Figure 1 of the drawing illustrates a practical fountain pen construction embodying the principles of this invention. In the illustrated type of pen the reference character 11 illustrates a pen holder with a conventional pen point 12 and feed bar 17 held in frictional engagement within the holder 11. A replaceable ink cartridge 13 is engaged with the pen holder 11 to supply a body of ink for the pen. The ink cartridge 13 is provided with a puncturable membrane 15 at the entrance end thereof to hold the ink within the cartridge prior to mounting the cartridge and the holder 11 as a cooperating fountain pen.

The pen holder 11 is provided with a threaded flange 19. A needle holder 20, provided with a hollow tubular needle 23, is threaded internally, as indicated by the reference character 21, to engage the threaded flange 19. The needle 23 has a feed hole 24 to receive ink.

The exterior surface of the holder 20 is threaded, as indicated by reference character 22.

An adapter sleeve 25 is threaded at one end, as indicated by reference character 26, to engage the exterior threads 22 on the holder 20. The end of the replaceable ink cartridge 13 is threaded, as indicated by reference character 14 to engage in the opposite end of the adapter 25, and engage interior threads 27 of the adapter.

As will be seen by referring to the drawing, whenever a new ink cartridge 13 is threaded into the adapter 25, the membrane 15 will be pierced by the needle 23 and will seal around the needle 23. However, the feed hole 24 will extend past the membrane 15 and allow ink to enter into the feed hole 24.

As-thus far described, the construction is not appreciably different from prior art construction wherein the needle serves also as an ink passageway to the nib and pen point. This construction is not satisfactory because it does not allow air to enter into the ink container to balance the vacuum created by the use of the pen, and therefore the ink flow is stopped. This difiiculty is avoided by the present invention.

In order to provide for an even flow of ink, the present invention permits air to enter into the ink cartridge 13 to replace that ink which is used. A longitudinal filler body 30 extends through the needle 23. This filler body substantially fills the hollow needle, except for a very small canal 31. The filler body extends almost to the puncturing point of the needle as illustrated in Figure 2.

On the surface of the filler body 30 facing the canal 31, as shown best in Figure 3 of the drawing, there is provided a longitudinal capillary feed path in the form of a plurality of capillary grooves 32. The areas defined in the grooves 32 are of quite small cross-sectional area, considerably smaller in size than the area of the canal 31. These grooves 32 form capillary canals which are sufficiently narrow that they can secure a uniform flow of ink to the pen. The canal 31 serves the purpose of conducting air to the interior of the ink cartridge 13. If the canal 31 for any reason should be filled with ink, the ink feed will still function. When the pressure within the cartridge 13 becomes sufiiciently low that no more ink leaves the cartridge, the ink in the canal 31 will draw into the capillary grooves 32 and will be led therefrom to the pen point. This process continues until an air passage through the canal 31 is again formed. When the air passage is opened the air pressure will be balanced within the cartridge by a fiow of air through the opened canal 31. Thereafter ink feed will proceed normally.

It has been found that the ink feed functions best when the filler body 30 is made of a material which has greater adhesion with the ink than the material of the hollow tubular needle 23. Hard rubber, sometimes referred to as ebonite, is a suitable material, but is not the only such material which has greater adhesion for ink than metal. Preferably the needle 23 is constructed of metal. The ink canals and the air canals do not initially have to constitute a continuous cavity as illustrated in Figure 3, but may be separated from one another, such as by providing narrow holes of different dimensions in a solid block.

In Figure 4 of the invention there is illustrated an alternate construction wherein a canal 36 passes centrally through a filler body 35, and a plurality of capillary grooves 37 are placed in radial fashion around the canal 36.

An additional desirable feature of this invention has been discovered in that the longitudinal grooves 32 may be shifted out of proper registration with the cooperating nib structure 17 or with the hole 24, or both, to restrict the flow of ink. Some inks are considerably more fluid 3 than others and this adjustment thereby provides for a regulation to suit the writing habits of the individual using the pen as Well as the characteristics of the ink in the pen.

Although the invention has been described in-its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only'by way of example and that numerous changes inth'e details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

A fountain pen construction, comprising, a permanent base assembly and a replaceable'barrel ink supply member, said base assembly having in internally threaded sleeve adapter, an externally threaded needle holder to fit said internal thread of the sleeve adapter, a needle carried by said holder, said needle extending through said holder, said needle having a tubular bore opening in the end of the needle on oneside of the holder and an opening in a side port on the other side of the holder, a needle pointprojecting beyond said side port, said holder threadably mounted in said-sleeve adapter near one end thereof with the needle extending coaxially of the adapter toward the opposite end, said needle holder being internally threaded on at least the end opposite said needle point,

a pen point and feed bar holder having external threads engageableinto'said internal threads of said needle holder,

a feed bar and pen point carried by said holder, an ink feed device to carry ink from said barrel to said feed bar and to admit air into said barrel in controlled amounts to meter ink output, said feed device comprising a filler body carried by said feed bar and insertable into said tubular bore in said needle, said filler body having a cross-sectional configuration filling all of said bore except an air bleed channel, the surfaces ofsaid filler body along said channel having capillary size isl'ots extending longitudinally thereof, and said barrel having an externally threaded end threadable intothe 'saidsleeve adapter opposite said pen and feed barzholder, said barrel having a puncturable member closing said barrel to retain an ink supply therein until pierced by said needle point.

References Cited in the file of this patent UNITED STATES PATENTS 2,045,774 Hirschy June 30, 1936 2,061,059 Carlson Nov. 17, 1936 2,229,749 Little Jan. 28, 1941 2,483,603 Wing Oct. 4, 1949 2,638,873 Woods May 19, 1953 FOREIGN PATENTS 21,631 Great Britain 1908 

